放電プラズマ焼結法によるFe-Co-Ga-P-C-Bガラス合金粉末のバルク化とその磁気特性

抄録

Fe₆₅Co₁₀Ga₅P₁₂C₄B₄ glassy alloy powders were produced by high pressure Ar gas atomization of Fe₆₅Co₁₀Ga₅P₁₂C₄B₄ alloy ingot prepared by induction melting. The glass transition temperature (T_g), supercooled liquid region (ΔT_x(=T_x-T_g)) of the glassy alloy powders are 730K and 50K. The glassy alloy powders have ferromagnetism with a Curie temperature (T_c) of 640 K and exhibits saturation magnetization (I_s) of 1.18 T. No appreciable difference in the thermal stability and magnetic properties is seen between the glassy alloy powders and the melt-spun ribbon. By spark-plasma-sintering (SPS) these glassy alloy powders under the pressure of 80 MPa and at the temperature of 723 K below T_g, a bulk glassy Fe₆₅Co₁₀Ga₅P₁₂C₄B₄ alloy with a size of 20 mm in diameter and 5 mm in thickness was synthesized. Its relative density was about 96%. There was also no appreciable difference in the thermal stability between the bulk glassy alloy and the glassy alloy powders. This bulk glassy alloy exhibited saturation magnetization (I_s) of 1.19 T and coercivity (H_c) of 115 A/m.